# Decoherence and pointer states in small antiferromagnets: A benchmark test

### Submission summary

 As Contributors: Hylke Donker Arxiv Link: https://arxiv.org/abs/1612.03099v3 Date accepted: 2017-02-24 Date submitted: 2017-02-17 Submitted by: Donker, Hylke Submitted to: SciPost Physics Discipline: Physics Subject area: Quantum Physics Approach: Computational

### Abstract

We study the decoherence process of a four spin-1/2 antiferromagnet that is coupled to an environment of spin-1/2 particles. The preferred basis of the antiferromagnet is discussed in two limiting cases and we identify two $\it{exact}$ pointer states. Decoherence near the two limits is examined whereby entropy is used to quantify the $\it{robustness}$ of states against environmental coupling. We find that close to the quantum measurement limit, the self-Hamiltonian of the system of interest can become dynamically relevant on macroscopic timescales. We illustrate this point by explicitly constructing a state that is more robust than (generic) states diagonal in the system-environment interaction Hamiltonian.

### Ontology / Topics

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Published as SciPost Phys. 2, 010 (2017)

### List of changes

1) The figures have been enlarged, in particular Figs. 2 & 5.

2) The units of time t is stressed in the captions of the figures.

### Submission & Refereeing History

Resubmission 1612.03099v3 on 17 February 2017
Resubmission 1612.03099v2 on 31 January 2017
Submission 1612.03099v1 on 12 December 2016